【摘要】 利用熔铸-原位反应喷射成形技术制备7075+TiC(2.91％,体积分数)铝合金半固态坯料,将合金加热到固液两相区不同温度,保温不同时间,淬火固定其半固态组织.采用扫描电镜观察其组织,应用ImageTool软件及截线法统计晶粒尺寸.研究表明,原位TiC颗粒不仅细化喷射成形组织,而且在二次加热保温过程中有效地阻碍晶界的移动,抑制了显微组织的粗化过程,在600℃保温60min后合金平均晶粒尺寸仍小于30μm,表现出良好的钉扎效应.更多还原

【Abstract】 The grain growth behavior of melt in-situ reaction spray deposited 7075+TiC (2.91%, volumic fraction) alloy were studied, and the effect of in-situ TiC particles on the microstructure of spray-formed 7075 alloy was investigated. The sectioned specimens were heat-treated isothermally at various temperatures between the solidus and liquidus of 7075 alloy for times in the range of 10-60 min, then quenched in water. The microstructure of reheated specimens was characterized using SEM and the grain size was measured using a mean linear intercept method. It is shown that the in-situ TiC particles can effectively control grain size even at 600℃ after 60 min.更多还原